STUDIES ON THE TERPENOIDS AND RELATED ALICYCLIC COMPOUNDS .44. TOTAL SYNTHESIS OF (+ -)-CEMBRANOLIDE VIA CR(II) MEDIATED INTRAMOLECULAR MACROCYCLIZATION OF BETA-ALKOXYCARBONYLALLYL HALIDE/
K. Nishitani et al., STUDIES ON THE TERPENOIDS AND RELATED ALICYCLIC COMPOUNDS .44. TOTAL SYNTHESIS OF (+ -)-CEMBRANOLIDE VIA CR(II) MEDIATED INTRAMOLECULAR MACROCYCLIZATION OF BETA-ALKOXYCARBONYLALLYL HALIDE/, Heterocycles, 36(9), 1993, pp. 1957-1960
The omega-formyl-beta-methoxycarbonylallyl halide (20), prepared from
geraniol and methyl beta-hydroxypropionate, was cyclized efficiently a
nd with high stereoselectivity to 14-membered cis-cycloalkenol (21) by
CrCl2 in DMF. The cycloalkenol was treated with p-TsOH to give an exc
ellent yield of (+/-)-cis-cembranolide (VI).