Abstract
The (+)-naphthoquinone epoxide (2) has been obtained by the phase-transfer chiral epoxidation of the naphthoquinone (1). Reduction of (+)-2 with sodium borohydride gives the (-)-cis-epoxyhydroxy ketone (3) and (-)-trans-epoxyhydroxy ketone (4). Further reduction of (-)-3 affords the (-)-cis-lactone (5), (-)-trans-lactone (6) and (+)-cis-epoxydiol (7). Alumina-induced lactonization of (+)-7 yields (-)-6. The 2S, 3R configuration for (+)-2 is deduced from the circular dichroism spectrum. The configurations of the 4-hydroxyl groups in (-)-3 and (-)-4 are determined by the Horeau's method.
