(2S)-1-phenylmethoxypent-4-en-2-ol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR112## and 2,5-anhydro-1,3-dideoxy-1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR113##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR112## and 2,5-anhydro-1,3-dideoxy-1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR113##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR112## and 2,5-anhydro-1,3-dideoxy-1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR113##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR111## and 2,5-anhydro-1,3-dideoxy-1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR112##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR112## and 2,5-anhydro-1,3-dideoxy1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR113##

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Copper(I)cyanide (120 mg, 1.34 mmol) was added to a solution of (R)-(-)-2-(benzyloxymethyl)oxirane (2.4 g, 14.6 mmol) in dry THF (200 ml). This mixture was cooled to -78° C. under argon atmosphere. A solution of vinylmagnesium bromide in THF (26 ml, 1M, 26 mmol) was added slowly to the epoxide solution at -78° C. The reaction mixture was stirred for 5 hours while the reaction temperature was allowed to warm to 0° C. Saturated aqueous NH4Cl and NH4OH were added to the reaction mixture till the reaction mixture became clear. Organic layer was separated and the aqueous layer was extracted with EtOAc (3×50 ml). Combined organic layers were dried over MgSO4 and concentrated. The residue was purified by chromatography (EtOAc/Hexane=1:9) to give 1-benzyloxy-2(S)-hydroxy-4-pentent (2.6 g, 13.5 mmol) NMR (CDCl3): 7.35 (bs, 5H), 5.84 (m, 1H), 5.14 (d, J=11, 1H), 5.11 (d, J=9, 1H), 4.57 (s, 2H), 3.90 (m, 1H), 3.53 (dd, J=3.4, 9.5, 1H), 3.39 (dd, J=7.4, 9.5, 1H) 2.29 (t, J=1.23, 2H). to warm to 0° C Organic layer was separated the aqueous layer was extracted with EtOAc (3×50 ml) Combined organic layers were dried over MgSO4 concentrated The residue was purified by chromatography (EtOAc/Hexane=1:9) to give 1-benzyloxy-2(S)-hydroxy-4-pentent (2.6 g, 13.5 mmol) NMR (CDCl3): 7.35 (bs, 5H), 5.84 (m, 1H), 5.14 (d, J=11, 1H), 5.11 (d, J=9, 1H), 4.57 (s, 2H), 3.90 (m, 1H), 3.53 (dd, J=3.4, 9.5, 1H), 3.39 (dd, J=7.4, 9.5, 1H) 2.29 (t, J=1.23, 2H)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The optically active tetrahydrofuran derivatives are prepared according to Scheme V. Benzyloxyacetaldehyde is reacted with optically active 2-allyl-1,3,2-dioxaborolane-4,5-dicarboxylic acid ester, XVII, to give optically pure (S)-1-phenylmethoxy-4-penten-2-ol, XVIII. Cyclization of alcohol, XVIII, with iodine in the presence of sodium bicarbonate gives a mixture of optically pure 2,5-anhydro-1,3-dideoxy-1-iodo-D-threopentitol, XIX, ##STR111## and 2,5-anhydro-1,3-dideoxy-1-iodo-D-erythro-pentitol, XX, which is separated by flash chromatography using silica gel. ##STR112##