929897-51-8Relevant articles and documents
Stereodivergent Hydroboration of Allenes
Nagashima, Yoshiyuki,Sasaki, Keiji,Suto, Takahiro,Sato, Takaaki,Chida, Noritaka
supporting information, p. 1024 - 1028 (2018/03/21)
Full details of a stereodivergent hydroboration of allenes are reported. While hydroboration of an allene with 9-BBN provided a thermodynamically stable (E)-allylic alcohol after oxidative work-up, the reaction of an identical allene with HB(Sia)2 (disiamylborane) formed a (Z)-allylic alcohol as the kinetic product. The developed conditions allowed for the synthesis of trisubstituted olefins in a highly stereoselective fashion, which is known to be challenging. The method was also applied to the stereodivergent synthesis of structural motifs such as skipped dienes and allylbenzenes, which are often embedded in biologically active natural products.
Synthesis of substituted resorcinol monomethyl ethers from 2-bromo-3-methoxycyclohex-2-en-1-ones
Shao, Wenjie,Clive, Derrick L. J.
, p. 3211 - 3216 (2015/03/30)
2-Bromo-3-methoxycyclohex-2-en-1-ones are readily alkylated at C-6 with reactive halides, and then treatment with DBU (2 equiv) in PhMe at room temperature results in smooth loss of bromide and aromatization to resorcinol monomethyl ethers of defined substitution pattern.
Synthesis of racemic Δ3-2-hydroxybakuchiol and its analogues
Shi, Lei,Lei, Xinsheng,Zhang, Jiange,Lin, Guoqiang
experimental part, p. 555 - 564 (2010/06/14)
The first synthetic approach to (±)-Δ3-2- hydroxybakuchiol (=4-[(1E,5E)-3-ethenyl-7-hydroxy-3,7-dimethylocta-1,5-dien-1- yl]phenol; 14) and its analogues 13a - 13f was developed by 12 steps (Schemes 2 and 3). The key features of the approach are the construction of the quaternary C-center bearing the ethenyl group by a Johnson - Claisen rearrangement (→6); and of an (E)-alkenyl iodide via a Takai - Utimoto reaction (→11); and an arylation via a Negishi cross-coupling reaction (→12e - 12f).
