Highly diastereoselective approach to novel phenylindolizidinols via benzothieno analogues of tylophorine based on reductive desulfurization of benzo[b]thiophene

Newly synthesized indolizine derivatives – antimicrobial and antimutagenic properties

“…HSQC and HMBC techniques Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 5/27/15 3:06 PM were used throughout the study for the assignment of the 1 H-13 C relationships. Preparation of compounds I-IV, VIII-XV, XVIII-XXI from L-glutamic acid was introduced in our previous papers (Marchalin et al, 1999(Marchalin et al, , 1993Šafář et al, 2009a, 2009b.…”

Synthesis and reductive desulfurization of chiral non-racemic benzothienoindolizines. An efficient approach to a novel bioactive tylophorine alkaloid analogue and 6-phenylindolizidine

“…1) of the targeted product 5. 8 Retrosynthetically (Fig. 2), the targeted compound 5 can be envisioned as coming from keto-amide 3 via a double ketone and lactam reduction.…”

“…Based on the reductive desulfurization technique of heterocyclic sulfur-containing rings, which is well known, 7,8 we anticipated that by the same procedure benzo[b]thieno [3,2-f]indolizines 3-5 and 9 (Scheme 1) could serve as a phenyl reservoir more suitable for the preparation of novel 6-phenylindolizidine and 6-phenylindolizidinol derivatives.…”

Studies on the synthesis of tetrahydropyrans via oxa-Michael addition leading towards the total synthesis of Montanacin D

“…40 Moreover, the reduction of thiophene using Ra-Ni is a powerful synthetic method for alkyl chain extension. [55][56][57][58] The reasons for placing the diol and epoxide (3.12) in their specific positions are strategic because trans-alkenes tend to give higher ees for dihydroxylation compared to cis substrates. Although Sharpless 39 has managed to devise a The second proposed synthetic pathway above (Scheme 15) begins with the construction of the precursor 3.8 to the Suzuki coupling.…”

“…Moreover, the easy reduction of thiophene using Ra-Ni is a powerful synthetic method for alkyl chain extension. [55][56][57][58] One of the key steps would similarly involve the Suzuki coupling 59 of two fragments (3.8 and The third proposed synthetic pathway (Scheme 24) would likewise begin with the construction of the Suzuki precursor 3.8 that was previously detailed in Section 3.3.2. The construction of the other Suzuki coupling partner starts with a Weinreb amide 3.30, followed by a Rh-catalysed 1,4-addition to give aldehyde 3.31.…”