Synthesis of (3aR, 4S, 5R, 6aS)-5-hydroxy-4-(hydroxymethyl) hexahydro-2H-cyclopenta[b] furan-2-one

Racemic 3, 3-dichloro-3, 3a, 6, 6a-tetrahydro-2H-cyclopenta[b] furan-2-one (4) is prepared in a yield of 65.3% from cyclopentadiene and dichloroacetyl chloride through a process of cycloaddition and Baeyer-Villiger oxidation. Through the resolution of racemic 4 by optically active phenethylamine (PEA) and Prins reaction with polyformaldehyde followed by the hydrolysis without separation, (3aR, 4S, 5R, 6aS)-3,3-dichloro-5-hydroxy-4-(hydroxymethyl) hexahydro-2H-cyclopenta[b] furan-2-one (6) is obtained in a 26.4% yield. (3aR, 4S, 5R, 6aS)-5-Hydroxy-4-(hydroxylmethyl) hexahydro-2H-cyclopenta [b] furan-2-one (2) is prepared in a 96.4% yield from 6 via the reduction with zinc dust.