Hirsutene

C₁₅H₂₄

Author	Tarun K. Sarkar
Publication year	1990
Synthesis type	Formal synthesis
Number of steps	16 (linear)
References	Tetrahedron Lett. 1990, 31, 3465. Tetrahedron 1992, 48, 6897.

Part 1 of 1

3,4-Dihydropyran, TsOH

Et₂O
Reflux, 5 h, 45 %

(COCl)₂, DMSO, Et₃N

CH₂Cl₂
-60 °C to RT, 50 min, 80 %

See the Swern Oxidation

TMS₂NNa

THF
-78 °C to RT, ON, 61 %

See the Wittig Reaction

TsOH

MeOH
Reflux, 90 min, 97 %

HCrO₃Cl^.Pyr, NaOAc

CH₂Cl₂
RT, 2 h, 87 %

(EtO)₂P(O)CH₂CO₂Et, NaH

DME
RT, 3 h, 76 %

See the Horner-Wadsworth-Emmons Reaction

Sealed tube

PhMe
245 °C, 30 h, 97 %

See the Ene Reaction

LiAlH₄

Et₂O
RT to Reflux, 5 h, 90 %

H₂Cr₂O₇^.2Pyr
4 Å MS

AcOH, CH₂Cl₂
0 °C to RT, 50 min, 82 %

NaH, DMSO, TMSI

THF
0 °C to RT, 2 h, 61 %

See the Johnson-Corey-Chaykovsky Reaction

TiCl₄

CH₂Cl₂
-78 °C, 60 min, 72 %

See the Hosomi-Sakurai Reaction

HCrO₃Cl^.Pyr

CH₂Cl₂
RT, 90 min, 70 %

O₂, PdCl₂, CuCl₂

DMF, H₂O
RT to 57 °C, 4.5 h, 77 %

See the Wacker Oxidation

KOH

EtOH, H₂O
55 °C, 90 min, 40 %

See the Aldol Condensation

H₂, Pt/C
1 atm

EtOAc
RT, 60 min, 98 %

Remaining...

70 % (1 step)

See: Tetrahedron Lett. 1976, 17, 195.