Acknowledgments. We gratefully acknowledge Pro- fessor William von E. Doering for his vital suggestion to attempt the acid-catalyzed transformation of 4 to 6 and fruitful discussions with Professors Ernest Wenkert and E. C. Taylor. ... 13, Rl=OH; R2-H 14, R1 = H; R2 = OH 15 16a, R1 = CH3C0, R2 = H 16b, R1 = H ; R2 = CH3C0 17a, Rt IC02Et, I$ = H 17b R1 = H; R2 I C02Et ... R -8& OH 0 18, R = COOEt 21, R1 I CH3; R2 I H 19, R = CHZOH 22, R1 = H; I$ ...