p-Toluenesulfonic acid → Hept-5-yn-1-ol

HRID 1513517Notes

Reaction equation

HRID 1513517 reaction equation
[CH2:1]([OH:7])[CH2:2][CH2:3][CH2:4][C:5]#[CH:6].[CH2:8]1C[O:12]C=C[CH2:9]1.[CH3:14][C:15]1[CH:16]=[CH:17][C:18](S(O)(=O)=O)=[CH:19][CH:20]=1.[Li]CCCC.CI>CCOCC.C1COCC1.C(Cl)Cl>[CH:1](=[O:7])[CH2:2][CH2:3][CH2:4][CH2:5][C:6]#[C:8][CH3:9].[CH2:16]([OH:12])[CH2:17][CH2:18][CH2:19][C:20]#[C:15][CH3:14]

Participants

10

Reactant 5

HCID 6101p-Toluenesulfonic acidHCID 6328Methyl iodideHCID 80803,4-dihydro-2H-pyranHCID 702345-Hexyn-1-olHCID 178418339Butyllithium

Product 2

HCID 9989234Hept-5-yn-1-olYield 61%HCID 86644212HCID 86644212, compound

Reagents, catalysts & solvents 3

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

Oct-6-ynal was synthesized according to the synthetic scheme of J. Yan, J. Zhu, J. J. Matasi, J. W. Herndon, J. Org. Chem. 1990, 55, 786 with additional THP-protection during the methylation step. Commercially available hex-5-yn-1-ol (15.2 g, 155 mmol) was protected (DHP, PTSA, CH2Cl2, 0° C.→room temp., 5 h), and subsequently methylated (1.6M BuLi, MeI, THF, −78° C.→room temp., 12 h). Cleavage of the THP ether (PPTS, MeOH, room temp., 12 h) afforded hept-5-yn-1-ol (10.6 g, 61%), which was mesylated (MsCl, Et3N, Et2O, 0° C.→room temp., 12 h) and subsequently cyanated (KCN, DMF, reflux, 3.5 h) to provide oct-6-yne nitrile (7.90 g, 69%). Reduction of this nitrile (DIBAL-H, THF, 0° C.→room temp., 12 h) furnished oct-6-ynal (6.70 g, 83%).

Sources & evidence

ORD record
ord-f75d262cb4be4da8ae041d59a8859096
Source dataset
uspto-grants-2012_07
Patent number
US08217185B2

Reaction notes

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