Jordi Gràcia

Dimethyl(methylthio)sulfonium fluoroborate induced cyclization of dithioacetals upon 2,3-disubstituted indoles

Abstract Treatment of dithioacetals 1a–c, 3, and 4 with DMTSF accomplishes cyclization upon the indole 3-position to give the Strychnos -type pentacles 2a–c, 10, and 11 , respectively.

The Fischer indolization of 2-azabicyclo[3.3.1]nonan-7-ones. A new entry to the dasycarpidan ring system

Abstract The regloselectivity of the Fischer indole synthesis from 2-azabicyclo[3.3.1]nonan-7-ones 4b–d using three different acid catalysts is studied, an ethyl substituent at the 9-position promoting indolization upon the C-8 carbon.

Stereocontrolled access to dasycarpidan-type compounds and formal total synthesis of Strychnos indole alkaloids of the Strychnan-type

Abstract An efficient, stereocontrolled synthesis of the tetracyclic bases 1 and 2 by cyclization of the regioisomeric cyanopiperidines 4 and 5 , prepared from the common cis -3-ethyl-4-(2-indolylmethyl)piperidine intermediate 3 , is reported.

Stereocontrolled synthesis of 4- and 9-ethyl-2-azabicyclo[3.3.1]nonan-7-ones via 2-cyanopiperidines

Abstract A stereoselective synthesis of 4- and 9-ethyl substituted morphans from 4-acetonyl-3-ethylpiperidines, involving the acidic cyclization of the corresponding 2-cyanopiperidines, is reported.

Total synthesis of the Strychnos alkaloid tubotaiwine

The total synthesis of racemic tubotaiwine 8 has been achieved from the tetracyclic intermediate 1, the key steps being the construction of the C(7)-quaternary centre by cyclization of a thionium ion upon the indole 3-position and the introduction of the C(16)-methoxycarbonyl substituent by photochemical rearrangement of the N-methoxycarbonylenamine 7.

A stereoselective total synthesis of dasycarpidan alkaloids: (±)-dasycarpidone, (±)-dasycarpidol and (±)-nordasycarpidone

A stereoselective total synthesis of the dasycarpidan alkaloids dasycarpidone 1, dasycarpidol 2 and nordasycarpidone 3 has been achieved from the tetracyclic intermediate 6, the key step being the oxidation of the C-6 methylene group.

Studies on the Synthesis of Strychnos Indole Alkaloids. An Efficient Stereocontrolled Synthetic Route to 2,4,8- and 2,8,9-Trisubstituted 2-Azabicyclo[3.3.1]nonan-7-ones☆

Abstract A stereocontrolled four-step synthesis of polysubstituted functionalized morphans 7 and 8 from the 3,4-cis piperidine derivative 1 is reported. β-Keto ester 1 was converted to 4-(oxopentyl)piperidines 3, and then to the 2-cyano derivatives 4 and 5, which were cyclized to the title compounds 7 and 8.