Efficient Synthesis of Jolkinolides A and B from Steviol

Jolkinolides, isolated from Euphorbia fischeriana Steud , are naturally occurring tetracyclic ent -abietane diterpenes, some of which exhibit promising antitumor and other biological activity. An efficient strategy for the synthesis of jolkinolides A and B is described starting from readily available steviol in 10 and 11 steps with total yields of over 10%, respectively.