Reaction of the cyclohexane-1,2-diols and methyl 4,6-O-benzylidene-α-D-gluco- and galacto-pyranoside with methylene halides

Abstract

Reaction of cyclohexane-cis-and trans-1,2-diol with methylene bromide (or chloride) in NN-dimethylformamide, in the presence of sodium hydride, yields cis-hexahydro-1,3-benzodioxolan and trans-hexahydro-1,3-benzodioxolan, respectively. In each case, small amounts of a 4,5:9,10-biscyclohexano-1,3,6,8-tetraoxacyclodecane were produced, together with some trans-hexahydro-1,3,5-benzotrioxepan from the trans-diol. Treatment of the diastereoisomeric forms of di-(trans-2-hydroxycyclohexyloxy)methane with methylene bromide under basic conditions gave low yields of tetraoxacyclodecane derivatives, one of which was identical with that formed on direct methylenation of cyclohexane-trans-1,2-diol. Methylenation, under basic conditions, of methyl 4,6-O-benzylidene-α-D-gluco- and 4,6-O-benzylidene-α-D-galacto-pyranoside gave, in each case, a 2,3-O-methylene derivative.