1574-34-1

Basic information

• Product Name: 3-methylenepent-1-yne
• Synonyms: 3-methylenepent-1-yne;2-Ethyl-1-butene-3-yne;3-Methylene-1-pentyne
• CAS NO: 1574-34-1
• Molecular Formula: C₆H₈
• Molecular Weight: 80.12772
• EINECS: 216-400-5
• Mol File: 1574-34-1.mol

Chemical Properties

• Boiling Point: 63.8°Cat760mmHg
• Flash Point: °C
• Appearance: /
• Density: 0.754g/cm³
• Vapor Pressure: 181mmHg at 25°C
• Refractive Index: 1.426
• CAS DataBase Reference: 3-methylenepent-1-yne(CAS DataBase Reference)
• NIST Chemistry Reference: 3-methylenepent-1-yne(1574-34-1)
• EPA Substance Registry System: 3-methylenepent-1-yne(1574-34-1)

Safety Data

• Hazardous Substances Data: 1574-34-1(Hazardous Substances Data)

Usage

InChI:InChI=1/C6H8/c1-4-6(3)5-2/h1H,3,5H2,2H3

Upstream product

• 56184-85-1 (2-ethyl-buta-2,3-dienyl)-diisopropyl-amine 
• 16356-04-0 3-methoxymethyl-penta-1,2-diene 
• 77-75-8 meparfynol 
• 10575-70-9 1-bromo-3-methyl-1,2-pentadiene 

Relevant articles and documents

What is the reason for the difference in Diels-Alder reactivity of isomeric substituted dienes? A case involving 1,3-dienylboronates

Correspondence and reprints Semi-empirical and ab initio calculations were run to account for the differences in reactivity of 1,3-dienylboronates 1, (E)-2 and (Z)-2 in the Diels-Alder cycloaddition with methyl acrylate. The results show that the s-cis conformation is accessed from the most stable s-trans, as easily for the unreactive (Z)-2 isomer as it is for the reactive (E)-2 isomer and for 1. Furthermore, the diene geometries and TT molecular orbitals in the s-cis conformation are not sufficiently affected by (Z) versus (E) substitution to explain the experimental observations. These results lead to the conclusion that variations in diene reactivity are most probably governed by steric repulsions in the Diels-Alder transition state in the case of (Z)-2. Diels-Alder / 1,3-dienylboronate / diene conformation / isoprene / steric constraint / ab initio calculation Eisevier,.

Surface-Mediated Reactions. 6. Effects of Silica Gel and Alumina on Acid-Catalyzed Reactions

Absorption of a variety of acids to chromatographic silica gel results in substantial enhancement of their catalytic activity-affording easily prepared, environmentally benign heterogeneous acids that are highly effective in mediating a number of processes.This was shown for the isomerization of allene 1 and dimerization of the corresponding 1,3-diene 2; cyclization of (R)-citronellal (5), the related diester 10, and 1,5-cyclooctadiene (15); Rupe rearrangement of alkynol 18; and Friedel-Crafts cyclodehydration of alcohols 21.By contrast, commercially available Nafion-H was significantly less effective as a heterogeneous acid catalyst.Chromatographic alumina displayed enigmatic behavior, showing enhanced acidity on the adsorption of HCl but little or no acidity on the adsorption of a variety of other types of acid.The results are discussed in terms of the surface structures of silica gel and alumina.

REACTIONS OF NITROGEN NUCLEOPHILES WITH 1-BROMOALLENES: REGIOSELECTIVE SYNTHESIS OF PROPARGYLAMINES

The results of a study on the reactivity of 3-alkyl- and 3,3-dialkyl-1-bromo-1,2-dienes 2 towards nitrogen nucleophiles, such as aqueous ammonia, lithium amide, aliphatic and aromatic amines allowed us to propose new methods for the synthesis of propargylamines, 1, with an available acetylenic hydrogen.The regio- and the stereoselectivity of these reactions are examined and possible mechanisms are discussed.