Alkyl enol ethers (AEE) are versatile synthetic intermediates with a unique reactivity pattern. This review article summarizes the synthesis of AEE as well as its reactivity and how enol ether undergoes intermolecular reactions for various bond formation, leading to the construction of several useful organic molecules. The synthetic applications of alkyl enol ethers towards intermolecular bond‐forming reactions include metal‐catalyzed reactions, cycloaddition and heterocycle formation as well as rwactions in the field of natural products synthesis. The achievement of these impressive transformations prove the countless synthetic potential of AEE. The main objective of this review is to bring attentiveness among synthetic chemists to show how AEE extensively can be used to react with both electrophiles as well as nucleophiles, thereby behaving as an ambiphilic reactant. We trust that the unique reactivity pattern of alkyl enol ethers and the fundamental mechanistic idea can attract chemists in AEE chemistry. Exclusively, intermolecular reactions of AEE with other functionalized moieties have not been reviewed to the best of our knowledge.

A facile one-step synthetic approach to dihydrofuro[3,2-c]chromenones and furo[3,2-c]chromenones by the reaction of methyl enol ethers with 4-hydroxy coumarin in a metal-free condition is presented. Dihydrofuro[3,2-c]chromenones and furo[3,2-c]chromenones were selectively obtained by controlling the stoichiometry of boron trifluoride diethyl etherate (BF3.Et2O). An unexpected aryl group migration followed by aromatization of furan moiety leading to a variety of furo[3,2-c]chromenone derivatives in good yields is reported.

The first total synthesis of acylphloroglucinol-based natural products faberiones A, B, and E is reported, which were isolated from Hypericum faberi. Total syntheses of faberiones A and B are accomplished in six linear steps from commercially accessible 1,3,5-trimethoxybenzene (methyl protected form of phloroglucinol) in overall yields of 31 and 33% respectively, via simple and straightforward approaches that include acylation, omethoxy deprotection, selective iodination and tandem-Sonogashira cyclization followed by C-geranylation. Faberione E is achieved in two linear steps from acylphloroglucinol with an overall yield of 57% via geranylation followed by benzopyran formation reaction.

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A mild and transition‐metal‐free one‐pot strategy is established to prepare polysubstituted naphthalene and phenanthrene derivatives from methyl enol ethers (MEE) with alkynes. Significantly, this protocol is promoted by boron trifluoride diethyl etherate (BF3⋅Et2O) at room temperature. A wide variety of diversely functionalized naphthalene and phenanthrene derivatives were obtained in good to excellent yields. A plausible mechanism involving a spiro quinonoid intermediate is proposed. Due to fluorescent nature of naphthalene, selected compounds were screened for the solvatochromism study. Notably, positive solvatochromism effect was observed in the case of nitro‐substituted naphthalene derivative (3 h) with respect to different polarity of solvents.