Synthesis of Erythrina and Related Alkaloids. XXVIII. Studies toward Total Synthesis of Non-aromatic Erythrina Alkaloids. (1). Synthesis and Isomerization of Unsaturated Bicyclic .DELTA.-Lactones.
SYNTHESIS IN THE FIELD OF THE ERYTHRINA ALKALOIDS: PART II. APPROACHES TO THE RING SYSTEM OF β-ERYTHROIDINE
作者:B. Belleau
DOI:10.1139/v57-095
日期:1957.7.1
The newly developed method for the elaboration of the ringsystem of the aromatic class of Erylhrina alkaloids has been successfully extended to the synthesis of 1,2,3,4-tetrahydroerythrinane (VI), a non-aromatic analogue. The key step in this synthesis involves ring closure of ketoamide (IV) itself, obtained from hexahydroindole and cyclohexenylacetic acid. Attempts to further extend this sequence
新开发的用于合成 Eryhrina 生物碱芳香类环系的方法已成功扩展到 1,2,3,4-四氢赤藓烷 (VI),一种非芳香类似物的合成。该合成中的关键步骤涉及从六氢吲哚和环己烯基乙酸中获得的酮酰胺 (IV) 本身的闭环。尝试将该顺序进一步扩展到使用 2H-5,6-二氢吡喃乙酸作为起始材料在后者的制备阶段遇到了失败。对图 III 所示的一种新的且不相关的逐步方法进行了研究,但在最终步骤中失败了。还简要描述了其他不成功的方法。
Ban et al., Chemical and pharmaceutical bulletin, 1968, vol. 16, # 3, p. 516
作者:Ban et al.
DOI:——
日期:——
Frosch; Harrison; Lythgoe, Journal of the Chemical Society. Perkin transactions I, 1974, vol. 0, # 17, p. 2005 - 2009
作者:Frosch、Harrison、Lythgoe、Saksena
DOI:——
日期:——
ANNIS G. D.; LEY S. V.; SELF C. R.; SIVARAMAKRIEHNAN R., J. CHEM. SOC. PERKIN TRANS., 1981, PART 1, NO 1, 270-277
作者:ANNIS G. D.、 LEY S. V.、 SELF C. R.、 SIVARAMAKRIEHNAN R.
DOI:——
日期:——
Synthesis of Erythrina and Related Alkaloids. XXVIII. Studies toward Total Synthesis of Non-aromatic Erythrina Alkaloids. (1). Synthesis and Isomerization of Unsaturated Bicyclic .DELTA.-Lactones.
As a model of the C/D ring system of erythroidines, bicyclic unsaturated δ-lactones were synthesized in a regio-selective manner, and their isomerization reaction in the presence of acid, base (DBU, 1, 8-diazabicyclo[5.4.0]undec-7-ene), and NaOH were studied. In the lactone form, the 6-ene (3) was the most unstable and isomerized to the 5-ene (1) then to the 1(6)-ene (2). The latter two lactones equilibrate to give ca. 3 : 2 mixture of 1 and 2 in the presence of DBU. On the contrary, in the opened form (NaOH), the lactone 1 was the most unstable and isomerized to 2 and 3. The 1(10)-ene (4) was inert under all of the conditions examined.